1. Field of the Invention
The disclosed concept relates generally to a molded case circuit breaker and, more specifically, to a molded case circuit breaker including a terminal shield wherein the terminal shield includes a position indicator than provides a visual indication that the terminal shield is not in a seated position when the circuit breaker terminal screws are not set.
2. Background Information
A circuit breaker, such as but not limited to a molded case circuit breaker, includes a non-conductive housing assembly that encloses a pair of separable contacts, an operating mechanism, a trip device, and other components. External to the enclosed space, the circuit breaker includes terminal, assemblies. The terminal assemblies are coupled to and in electrical communication with, conductors that extend into the enclosed space and are in electrical communication with the separable contacts. The terminal assemblies further include a conductive terminal body. The terminal body is structured to be coupled to, and placed in electrical communication with, an external conductor, typically a line or load conductor.
The external conductor may be, but is not limited to, a generally cylindrical cable. As such, the terminal assembly body may define a circular bore or opening into which the cable may be placed. Alternatively, the external conductor may be a bus bar having a rectangular cross-section. Thus, a terminal assembly body may also define a rectangular opening.
The terminal assembly further includes a terminal screw. The terminal screw is movably coupled to the terminal and is structured to secure the external conductor to the terminal body. That is, the terminal screw is structured to move between two positions, a first position, wherein the terminal screw is not set, and a second position, wherein the terminal screw is set. For example, the terminal body may include a threaded bore that is contiguous with the opening for the external conductor, When the terminal screw is in the first position, the terminal screw does not bias the external conductor against the terminal body. When the external conductor is disposed in the terminal body bore, or other opening, and the terminal screw is moved into the set, second position, the terminal screw biases the external conductor against the terminal body. That is, the terminal screw is drawn tight against the external conductor. In this configuration, the external conductor provides a secure connection to the terminal assembly body.
The terminal screw is, typically, disposed in a bore in the circuit breaker housing, or, is structured to have a terminal shield placed thereover. As such, the terminal screw, and more specifically the position of the terminal screw, may not be visible. This may lead to a situation wherein the terminal screw is not in the second position. For example, during installation of the circuit breaker, a user may position the external conductor in the terminal body but may choose to not tighten the terminal screw initially or may simply forget to tighten the terminal screw at that time. With the terminal screw position not visible, the user may forget, or not notice, that the terminal screw is not in the second position. If the circuit breaker is used in this configuration, the electric coupling may become damaged, overheat, damage the external conductor, may become dangerous during an over-current (fault) condition, or suffer from other detrimental effects of an external conductor that is not sufficiently biased against the terminal.
As such, there is a need for an indicator structured to indicate the position of the terminal screw. There is a further need for an indicator that is simple to construct and operate.